WO2007105962A1

WO2007105962A1 - Method and device for the strapping of a pipe

Info

Publication number: WO2007105962A1
Application number: PCT/NO2007/000102
Authority: WO
Inventors: Pål Espen ANTONSEN
Original assignee: Industrikonsult As
Priority date: 2006-03-16
Filing date: 2007-03-15
Publication date: 2007-09-20
Also published as: NO20061224L; NO325195B1

Abstract

A method and device for strapping of pipes (6, 8) during an offshore pipe laying operation, where straps (28, 30) are encircled, tightened and locked around the pipe (6, 8) by a strapping apparatus (2) located in a first position, and where, during the strapping operation, the strapping apparatus (2) is displaced essentially at the same speed as the pipe (6, 8) and in the direction of displacement of the pipe (6, 8).

Description

METHOD AND DEVICE FOR THE STRAPPING OF A PIPE

This invention regards a method of strapping pipes. More particularly, it regards a method of strapping pipes during an offshore pipe laying operation, where straps are encircled, tightened and locked around the pipe by a strapping apparatus being in a first position. During the strapping operation, the strapping apparatus is displaced essentially at the same speed as the pipe and in the direction of displacement of the pipe. The invention also comprises a device for exerting the method.

It may become necessary, during offshore pipe laying operations, to strap parts to the pipe, e.g. to attach a pipe to another pipe, a so-called piggy-back, or to couple other parts to the pipe.

In prior art, straps are fitted to the pipe or pipes either manually or by means of a stationary strapping apparatus.

Preferably the deployment of pipe from a lay barge is performed as a continuous operation. Fitting straps by means of a stationary strapping apparatus requires the deployment to be interrupted while the strapping operation is going on.

Manual fitting of straps is a relatively labour intensive operation and entails a considerable risk of personal injury, as the work is carried out on moving pipes. For this reason, manual strapping is avoided as far as possible.

Thus, fitting metal straps by use of prior art leads to a reduction in productivity and/or an unacceptable risk of personal injury.

The object of the invention is to remedy or reduce at least one of the drawbacks of prior art.

The object is achieved in accordance with the invention, by the features indicated in the description below and in the following claims.

According to the invention, a method of strapping pipes during an offshore pipe laying operation, in which method straps are encircled, tightened and locked around the pipe by means of a strapping apparatus being in a first position, is characterized in that during the strapping operation, the strapping apparatus is displaced essentially at the same speed as the pipe and in the direction of displacement of the pipe.

After the strapping operation has been completed, the strapping apparatus is moved back to the first position.

If the straps used come from a coil, the strapping operation also includes cutting the strap after locking.

The actual strapping apparatus is known per se, and thus will not be described in greater detail past the fact that when strapping is to be carried out, it moves the strap through a track which is prearranged around the pipe. The tension device of the strapping apparatus will then grip the free strap end portion of the strap, the strap being pulled radially out of the track and tightened prior to being locked, typically by means of a clamping piece. i A strapping machine of the invention comprises a guide frame in addition to the strapping apparatus . The guide frame is arranged to displace the strapping machine in parallel with the pipe during the strapping operation.

Most preferably, the guide frame is provided with driven, lockable wheels that abut the pipe, and which, through use of friction, keep the strapping machine stationary relative to the pipe during the strapping operation. Furthermore, the wheels are arranged to roll against the pipe when the strapping machine returns to the first position.

If so desired, the guide frame may be provided with grippers arranged to grip the pipe during the strapping operation. Alternatively the guide frame may be displaced along separate guides by an actuator.

Advantageously the strapping machine can be controlled manually or automatically to arrange straps at the required intervals along the pipe, based on measurements of pipe length and programming. The straps may also be used to keep support blocks in place, in a manner that is known per se, e.g. when it comes to strapping together several parallel pipes .

The method and the device according to the invention make a 5 pipe laying operation significantly more efficient, especially when several pipes are to be strapped together, and at the same time the risk of personal injury during the strapping operation is essentially eliminated.

The following describes a non-limiting example of a preferred io method and embodiment illustrated in the accompanying drawings, in which:

Fig. 1 is a plan view of pipes being laid, where a strapping machine in accordance with the invention is about to place a metal strap around the pipes;

is Fig. 2 is a somewhat scaled-up sectional view along I-I in Figure 1; and

Fig. 3 is a side view of the machine of Figure 1, also on a slightly larger scale.

In the drawings, reference number 1 denotes a strapping 20 machine comprising a strapping apparatus 2 and a guide frame 4, the strapping machine of Figure 1 being shown in the process of strapping a first pipe 6 to a second smaller pipe 8.

-^ The guide frame 4 comprises a strapping apparatus support 10 25 which is coupled to adjacent equipment (not shown) , and which comprises guides for the strapping machine 1, and from which the strapping machine 1 is supplied with necessary power. The connection is indicated by a hatched area 12 in Figure 1. This adjacent equipment (not shown) may also comprise auxiliary guides for the strapping machine 1.

Moreover, the guide frame 4 comprises two wheel mounts 14, one on either side of the strapping apparatus support 10, seen in the longitudinal direction of the first pipe 6.

The lower portion of the wheel mount 14 partially enclosing the first pipe 6 is provided with a free running first support wheel 16, see Figure 2. Arranged at a distance from the first support wheel 16 and along the periphery of the first pipe 6 and on either side of the first support wheel 16, are driving wheels 18.

In this preferred embodiment the driving wheels 18 are connected to respective hydraulic motors 20.

Two second support wheels 22 at the upper part of the wheel mount 14 abut the second pipe 8 in a supportive and guiding manner, the second support wheels 22 being in a pivotable clamping frame 24. The clamping frame 24 is coupled to the wheel mount 14 by a rotary shaft 26. The second support wheels 22 are pressed against the second pipe 8 by an actuator (not shown) , the clamping frame 24 pivoting with respect to the wheel mount 14, about the rotary shaft 26. This pretensioning also causes the first support wheel 16 and the driving wheels 18 to be pressed against the first pipe 6.

In Figure 1, a first strap 28 has been strapped around the first pipe 6 and the second pipe 8, the pipes 6, 8 being continuous fed out .

The second support wheels 22 maintain the second pipe 8 at the desired position relative to the first pipe 6. The driving wheels 18 are controlled so as to rotate at a peripheral speed which corresponds to the rate of feed of the pipes 6, 8, but in the opposite direction, so that the strapping machine 1 is in its first position.

When a second strap 30 is to be fitted to the pipes 6, 8 the rotation of the driving wheels 18 is stopped and braked, whereby the strapping machine 1 moves with the pipes 6, 8.

The strapping apparatus 2 fits the second strap 30 while the strapping machine is stationary relative to the pipes 6, 8, while the pipes 6, 8 are being deployed.

When the second strap 30 has been fitted the driving wheels 18 are rotated at the required speed to allow the strapping machine 1 to move back to the first position along the pipes

Claims

C l a i m s

1. A method of strapping pipes (6, 8) during an offshore pipe laying operation, where straps (28, 30) are encircled, tightened and locked around the pipe (6, 8) by a strapping apparatus (2) being in a first position, c ha r a c t e r i z e d i n that during the strapping operation, the strapping apparatus (2) is displaced essentially at the same speed as the pipe (6, 8) and in the direction of displacement of the pipe (6, 8) .

2. A method in accordance with Claim 1, c ha r a c t e r i z e d i n that after the strapping operation has been completed, the strapping apparatus (2) is returned to the first position.

3. A method in accordance with Claim 1, c ha r a c t e r i z e d i n that the strapping apparatus (2) is controlled manually or automatically to arrange straps (28, 30) at required intervals along the pipe (6, 8), based on measurements of pipe length and programming.

4. A device for strapping pipes (6, 8) during an offshore pipe laying operation, where straps (28, 30) are encircled, tightened and locked around the pipe (6, 8) at intervals by a strapping apparatus (2) being in a first position, c ha r a c t e r i z e d i n that a strapping machine (1) comprises a guide frame (4) in addition to the strapping apparatus (2), the guide frame (4) being arranged to displace the strapping machine (1) in parallel with the pipe (6, 8) during the strapping operation.

5. A device in accordance with Claim 4, ch a ra c t e r i z e d i n that the guide frame (4) comprises a strapping apparatus support (10) and y^ at least one wheel mount (14) provided with a driving wheel (18) .

6. A device in accordance with Claim 5 , ch a ra c t e r i z e d i n that the driving wheel (18) is lockable .

7. A device in accordance with Claim 4, c h a r a c t e r i z e d i n that the wheel mount x

(14) is provided with grippers arranged to grip the pipe (6, 8) .

8. A device in accordance with Claim 5, y- cha r a c t e r i z e d i n that the wheel mount (14) is provided with a clamping frame (24) .

9. A device in accordance with Claim 5 , char ac t e r i z ed in that the clamping frame (24) is provided with second support wheels (22) .